OF ALL THE LOOTED SITES in the world, none may be as serious, or as heartbreaking, as the pillaging of the area around Djenné, a city in the northern African nation of Mali, where nearly half of all archaeological sites have been plundered. Because of its dry climate, the area contains the second-largest concentration of antiquities in Africa.

The inland Niger River Delta, which includes much of Mali, has been inhabited since at least 250 BC. Djenné was a major trading center between Timbuktu to the north, and the forest regions to the south. Enriched by waves of immigration and conquests, Djenné became a center of Islamic learning and is known today for its unusual red brick mosque.

Entire villages of several hundred people are often hired to pick through burial mounds in search of high quality terra cotta figures and pottery, often dating to the 13th century.